Bag type dust collector



1967 E. w. BULLOCK ETAL BAG TYPE DUST COLLECTOR 5 Sheets-Sheet 1 Filed Aug. 19, 1965 I N VE NTOR. I Bullock BY William E. Driver 52A WZ M Allonggqs.

Oct. 10, 1967 E. w. BULLOCK ETAL. 3,

BAG TYPE DUST COLLECTOR Filed Aug. 19, 1965 I s Sheets-Sheet 2 a 36 3 3 3759 A +2 5 f 38/ 7 415 INVENTOR.

Ell/1S" w; Bullock BY W/IiiamE. Driver \\\\\\\\\\\\Y\\\\\\\\\\\ fw {F 64 v Af/ongggg 1967 E. w. BULLOCK ETAL BAG TYPE DUST COLLECTOR Sheet 3 5 Sheets Filed Aug. 19, 1965 INVENTOR.

w Mu OWE. mm 6 MW United States Patent 3,345,806 BAG TYPE DUST COLLECTOR Ellis W. Bullock and William E. Driver, Birmingham, Ala., assignors to The Fly Ash Arrestor Corporation, a corporation of Alabama Filed Aug. 19, 1965, Ser. No. 481,036 4 Claims. (Cl. 55-293) Our invention relates to apparatus of the bag type for separating dust and the like from a stream of gas bearing the same.

In the art to which our invention relates, it has been customary in bag type filters to mount a plurality of bags inside a housing and to pass the dirty air from the outside of the bags, whereby dust collects on the outer surfaces of the bags. In such apparatus the bags are stationary and a travelling blowback hood passes successively over the open upper ends of the bags whereby the dirt is blown from the outer walls of the bag and collected in a hopper.

An object of our invention is to provide a bag type collector embodying a plurality of individual, generally vertically disposed bags open at their bottoms into which the dust laden gas is passed, together with means to rotate the bags whereby they are brought successively beneath a blowback hood which blows air downwardly between at least a pair of the bags, whereby the dirt from'the inside of the bags is removed through a lower, cooperating hopper.

A more general object of our invention is to provide a bag type filter embodying a plurality of separate bags together with means to move the bags While the outer housing in which they are mounted is stationary, together with means to provide an adequate air-tight seal between the two housings.

A further object of our invention is to provide an improved means for detachably mounting the individual filter bags in such manner that they may be conveniently and quickly removed for replacement or repair as required.

Specifically, we propose to secure the bags at the upper and lower ends by means of hookless fasteners, the slide portions of the fasteners at the top being accessible from the outside of the bag, whereas the slide portion of the fasteners at the bottom are accessible from inside the bags, all for a purpose later to appear.

Apparatus illustrating features of our invention is shown in the accompanying drawings forming a part of this application in which:

FIG. 1 is a vertical sectional view, partly broken away, and showing our improved filter;

FIG. 2 is a fragmental detail sectional view taken generally along the line IIH of FIG. 1;

FIG. 3 is a detail fragmental view taken generally along line III-I*II of FIG. 1; 7

FIG. 4 is a detail sectional view taken generally along line IVIV of FIG. 1;

FIG. 5 is a view taken generally along line VV of FIG. 1, and drawn to a slightly smaller scale;

FIG. 6 is an enlarged detail fragmental view taken general-1y along line VIV-I of FIG. 2 and illustrating the means for connecting the upper ends of the bags to the carrier;

FIG. 7 is a detail fragmental view taken generally along lines V'II-VII of FIG. 3 and illustrating the method of securing the bags to the carrier at the lower ends thereof;

FIG. 8 is a detail fragmental sectional view through the upper end of one of the bags and the associated portions of the carrier;

FIG. 9 is a fragmental isometric view showing one of the roller supports for the bag carrier; and,

FIG. 10 is an enlarged detail sectional view of that portion of the structure enclosed generally within the dotted circle of FIG. '1, labelled X-X.

Referring now to the drawings for a better understanding of our invention, our improved carrier comprises generally an outer, cylindrical housing 10 which is mounted in stationary fashion on supporting posts or the like indicated at 11. The housing 10 may embody a sloping transition piece or section 12 having an inlet connection 13 through which the dirt bearing gas is admitted. A diffusion plate 14 may be provided, properly to distribute the gases within the housing 10. Further, the housing 10 may be provided with a removable closure 16 covering an access opening 17 therein.

Mounted as will be explained in the outer housing 10 is the bag carrier, which is indicated generally by the numeral 18. The bag carrier 18 embodies generally a cylindrical housing 1 9. At the bottom of the housing 19 is a plate 21 which has an outer series of radial-1y elongated openings 22 therein and an inner series of shorter, radially elongated openings 23 therein. The purpose of these openings will later be described.

At the upper end the bag carrier housing is provided with a circular angle 24, welded or otherwise secured to the upper edge of the cylinder 19. A circular plate 26 is welded or otherwise secured to the horizontal leg of the angle 24. The circular plate has a plurality of curved cutouts 27 on the inner edge thereof. inwardly of the plate 26 is a second horizontal, circular plate 28 which has a plurality of curved cutouts 29 on its outer edge and a similar series of cutouts 31 on its inner edge. At the center of the bag carrier housing 19 is a vertically hollow center column 32 covered at its top with a plate 63, the column 32 resting at its bottom on the lower plate 21.

Disposed to fit removably in the cutouts 27, 29 are'depending radially elongated flange members 34. Similar, radially elongated but shorter flange members 36 are removably positioned in the cutouts 31 of the intermediate circular plate 28 and the edges of the plate 33. Glued or otherwise secured to the inner surfaces of the flanges 34 are boot-like members 37 which carry at their lower edges one-half 38 of hook-less slide fasteners indicated generally by the numeral 39. In similar manner, boot-like members 41 are secured inside of the flange members 36 and carried one half 42 of hookless slide fasteners indicated generally by the numeral 43. The flange members are supported from the plates'61 and 62 later to be described.

As best shown in FIG. 7, the openings 22 in the lower plate 21 are surrounded by vertically upstanding flange members 44 which are welded or otherwise secured airtight to the upper surfaces of plate 21. Similarly, surrounding the smaller inwardly disposed openings 23 are flange members 46 which are welded to the surface of the plate 21.

Secured to the outer surfaces of the upstanding flange members 44 are boot-like members 47 which carry onehalf 48 of hookless fasteners 49. In similar manner, bootlike members 51 surround the outer sides of the upstanding flange members 46 and carry at their upper edges one-half 52 of hookless fasteners indicated generally at 53.

The filter bags proper are indicated by the letters B and B-1. At their lower ends the bags B and B-1 carry, respectively, the upper halves 48 and 52 of the hookless fasteners and the parts are joined by the slides 54 and 56, respectively. It is to be especially noted that the slides 54 and 56 at the bottom of the bags B and B-1 are on the insides of the bags. They thus are accessible for manipulation through the openings 22' and 23, as will presently appear.

At their upper ends the bags B and B-1 carry, respectively, the other halves 38 and 42 of hookless fasteners. The halves 38 and 38 are provided with the usual slide 57 while the halves 42 and 42 of the bags B-l carry the a a usual slide 58. The slides 57 and 58 are on the outer sides of the respective bags.

Secured by means of bolts 59 or the like to the circular rings 26 and 28 are coverplates 61 which seal the upper ends of the bags B airtight to these plates the flange members 34 and secured in airtight manner as by welding. Similarly, plates 62 are held by bolts 59 in airtight manner over the upper ends of the bags B-1, and the flange members 34 are welded thereto.

As before stated, one of the prime objects of our invention is to mount the bag carrier so that it is rotatable about its vertical axis, whereby the bags may be brought successively under a blowback hood. To this end, we provide at the lower end of the outer cylinder or housing a circular track 63 which is supported in suitable manner on framework indicated at 64 and which may embody a vertically disposed, circular inner member 66. Secured at intervals along the outer periphery of the bottom plate 21 are a plurality of horizontal support plates 67 beneath which are spaced, depending plates 68. Journaled between the plates 68 are rollers 69, conical in configuration and which ride on the track 63. The plates 67 may be strengthened by gusset plates 71 which are welded to the sides of the bag carrying housing 19.

Depending from the plate 21 adjacent its outer periphery is a circular plate 72. Plate 72 runs in a trough 73, and the trough may be filled with liquid such as mercury, indicated at 74 in FIG. 10. It will thus be apparent that the plate 72 and the mercury filled trough 73 provide an airtight seal between the outer housing 10 and the inner, revolvable bag carrier 19.

The circular bag carrier 18 is provided with a circular gear 76. A pinion 77 mounted in suitable bearings as illustarated in FIG. 1 may be driven through a reduction gear box 78 by a motor or the like 79.

The top of the outer housing 10 may be covered by cone-shaped section 81 which has an outlet 82 for the clean gas. Passing through the sloping top wall of the section 81 is a blowback hood indicated at 83. The hood 83 has its lower end riding in close proximity to the tops of the plates 61 and 62, whereby, as the bags rotate beneath the blowback hood, air is blown downwardly through the spaces 84 and 86 between the respective plates 61 and 62.

Passing through the bottom closure 16 is a conduit 87 which is vertically aligned with the blowback hood 83. As best illustrated in FIG. 5, the lower conduit 87 may be wider than the blowback hood 83.

Another important feature of our invention is the fact that for removing the dust from the bags we use cleaned system air. We accomplish this by means of a conduit 88 connected to the upper housing closure 81 from which clean air may be drawn by blower 89 and then passed into the blowback hood 83. Thus, as the bags rotate as will presently appear, clean system air is blown through the spaces 84 and 86, on the outer sides of the bags, from whence it passes into the bags, whereby the dirt from the bags is delivered from their lower, open ends into the dustcollecting conduit 87. Thus, instead of using outside moisture taken in for cleaning, we use gas having the same moisture and temperature existing within the system.

From the foregoing the manner of constructing and using our improved dust collector together with the advantages thereof may now be more fully explained and understood.

First, with respect to the bag-supporting feature, it will be seen that the upper hood 81 may be provided with an opening 92 removably closed by a door or the like 93. When it is desired to change the bags, or to repair them, it is only necessary for the operator to remove the lower door 17 whereby he may enter the space beneath the bags and, reaching through the openings 22 and 23, has complete access to the slide fasteners 54 and 56 which may be unzipped. By removing the door 93 and the bolts 59 the bags may be lifted out with the plates 61 and 62, access being had through the opening 92 for this pur pose. With the bags pulled upwardly, or completely removed from the apparatus if desired, they may be repaired or new ones maybe installed, it being noted again that the slides 57 and 58 at the upper ends of the bags are accessible from the outer sides of the bags.

In operation, blower 89 is run continuously, thereby to draw clean air from the upper part of the housing 10. As it is blown downwardly through the blowback hood 83, it passes through the spaces 84 and 86 between the top plates 61 and 62 which support the bags at their upper ends, whereby clean air enters the bags from the outside, thus causing the dust which has been collected on the insides to fall into the collecting conduit 87. It further will be understood that the upper or mouth end of conduit 87 runs in close proximity to the lower surface of the plate 21 as illustrated in the drawings. Therefore, clean blowback air is supplied to at least the adjacent surfaces of two adjacent bags of each group, simultaneously, and such dust as is removed falls into the conduit 87 to be carried away. Our invention thus differs from previous bag collectors in that we rotate the bags instead of having the complicated machinery necessary to rotate the blowback hood and further in that we blow clean air from the outside of the bags to the inside to remove the dirt or dust.

From the foregoing, it will be apparent that we have devised an improved bag-type dust collector. Our invention is characterized by its simplicity of construction and operation and by the fact that the bags are quite readily change or replaced when desired. Further, the liquid filled trough at the lower end of the rotating bag carrier provides an economical, dependable airtight seal between the stationary outer housing and the moving inner bag carrier.

While we have shown our invention in but one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof, and we desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What we claim is:

1. In a bag filter,

(a) an outer cylinder-like housing having an inlet at its lower end for dust bearing gas,

(b) a cylinder-like bag carrier mounted inside the outer housing for rotation about its longitudinal axis and having a lower wall,

(0) a plurality of spaced-apart generally radially disposed bag supporting members at the top of the bag carrier,

(d) there being a plurality of openings in the lower wall of the bag carrier,

(e) a plurality of filter bags open at their lower ends in communication with the openings in said lower wall, said bags being closed at their upper ends and affixed to the bag supporting members,

(f) a blowback hood disposed to blow gas downwardly around the outer sides of adjacent pairs of said bags, whereby dust collected therein is blown downwardly and passes beneath the lower wall of the bag carrier,

(g) a dust collecting conduit in alignment with the lower ends of the bags receiving said blowback gas,

(h) means to rotate the bag carrier, thereby to bring the spaces between adjacent bags successively under the blowback hood, and

(i) means to maintain a gas tight seal between the outer housing and the bag carrier.

2. Apparatus as defined in claim 1 in which the bag carrier is mounted for rotation on a circular track located inside the outer housing, adjacent the lower end of the latter, the means to seal between the outer housing and the bag carrier comprising a circular trough filled with liquid and located adjacent the bottom of the outer 5 housing, and a circular bafile carried by the bag carrier disposed in said trough with its lower edge beneath the surface of liquid in the trough.

3. Apparatus as defined in claim 2 in which said liquid is mercury.

4. Apparatus as defined in claim 1 in which the blowback gas is clean gas supplied from within the outer housing.

References Cited UNITED STATES PATENTS 6 2,854,091 9/1958 Roberts et al. 55-341 3,303,636 2/1967 Liel 55294 FOREIGN PATENTS 874,986 6/ 1942 France.

OTHER REFERENCES Pneumatic Conveying in Chemical Engineering, pages 151-153, May 10, 1965.

HARRY B. THORNTON, Primary Examiner,

B. NOZICK, Assistant Examiner. 

1. IN A BAG FILTER, (A) AN OUTER CYLINDER-LIKE HOUSING HAVING AN INLET AT ITS LOWER END FOR DUST BEARING GAS, (B) A CYLINDER-LIKE BAG CARRIER MOUNTED INSIDE THE OUTER HOUSING FOR ROTATION ABOUT ITS LONGITUDINAL AXIS AND HAVING A LOWER WALL, (C) A PLURALITY OF SPACED-PART GENERALLY RADIALLY DISPOSED BAG SUPPORTING MEMBERS AT THE TOP OF THE BAG CARRIER, (D) THERE BEING A PLURALITY OF OPENINGS IN THE LOWER WALL OF THE BAG CARRIER, (E) A PLURALITY OF FILTER BAGS OPEN AT THEIR LOWER ENDS IN COMMUNICATION WITH THE OPENINGS IN SAID LOWER WALL, SAID BAGS BEING CLOSED AT THEIR UPPER ENDS AND AFFIXED TO THE BAG SUPPORTING MEMBERS, (F) A BLOWBACK HOOD DISPOSED TO BLOW GAS DOWNWARDLY AROUND THE OUTER SIDES OF ADJACENT PAIR OF SAID BAGS, WHEREBY DUST COLLECTED THEREIN IS BLOWN DOWNWARDLY AND PASSES BENEATH THE LOWER WALL OF THE BAG CARRIER, (G) A DUST COLLECTING CONDUIT IN ALIGNMENT WITH THE LOWER ENDS OF THE BAGS RECEIVING SAID BLOWBACK GAS, (H) MEANS TO ROTATE THE BAG CARRIER, THEREBY TO BRING THE SPACES BETWEEN ADJACENT BAGS SUCCESSIVELY UNDER THE BLOWBACK HOOD, AND (I) MEANS TO MAINTAIN A GAS TIGHT SEAL BETWEEN THE OUTER HOUSING AND THE BAG CARRIER. 